A new study suggests that the coronavirus that causes COVID-19 may hide in the brain of infected people and cause relapses in patients who appeared to be recovering.
In a study published Tuesday by the journal Virus, researchers at Georgia State University found that mice infected with the virus through their nasal passages developed a serious illness due to brain infection, even after the virus left their lungs. The lead researcher and co-author of the study, Mukesh Kumar, suggested that the findings could explain why human patients who appear to be almost overcoming the disease sometimes relapse quickly and die.
“The brain is one of the regions where the virus likes to hide,” said Kumar in a press release. “That’s why we are seeing serious illness and all these multiple symptoms like heart disease, stroke and all those long periods of loss of smell, loss of taste … It all has to do with the brain, not the lungs. “
The study found that the virus was located in the brain of mice at a level 1,000 times greater than in any other area of the body. While the levels of the virus located in the lungs began to decrease after three days of infection, the virus remained at high levels in the brain on the fifth and sixth days, when the course of the disease worsened.
“Our thought that it is more of a respiratory disease is not necessarily true,” said Kumar. “Once it infects the brain, it can affect anything because the brain is controlling its lungs, the heart, everything. The brain is a very sensitive organ. It is the central processor of everything.”
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In addition to COVID-19, Kumar suggests that coronavirus reaching the brain may make patients susceptible to other serious health problems in the future, including neurological conditions like Parkinson’s disease and multiple sclerosis, along with general cognitive decline and autoimmune diseases.
“It’s scary,” he said. “Many people think they have taken COVID and recovered and are now out of danger. Now I feel it will never be true. You can never be out of danger.”
Neurological symptoms are relatively common in people with COVID-19. However, while several studies have suggested that rat brains are susceptible to infection by the virus, the research has not produced conclusive evidence to support the notion that the virus infects and focuses on the human brain. Neurological symptoms can be caused by an immune response, rather than a direct brain infection.
A blog post written by the Director of the National Institute of Health, Dr. Francis Collins last week, detailed a recent study conducted by the National Institute of Neurological Diseases and Stroke that found brain damage in tissue samples from 19 people who died of COVID- 19, but without evidence that the virus infected the brain tissue itself.
“The findings are especially intriguing because there has been some suggestion based on studies in mice that SARS-CoV-2 may cross the blood-brain barrier and invade the brain,” wrote Collins, before noting that another study, published in the Journal of Experimental Medicinefound evidence of the virus in the brains of three people who died of complications from COVID-19.
“Clearly, more research is needed, ” Collins added. “As we learn more about the various ways in which COVID-19 wreaks havoc on the body, understanding neurological symptoms will be instrumental in helping people. “